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Comparing deliantra/server/include/shstr.h (file contents):
Revision 1.23 by root, Sun Dec 28 06:59:27 2008 UTC vs.
Revision 1.24 by root, Wed Dec 31 17:35:37 2008 UTC

… …
20 */ 20 */
21 21
22#ifndef SHSTR_H__ 22#ifndef SHSTR_H__
23#define SHSTR_H__ 23#define SHSTR_H__
24 24
25#include <cstring>
25#include <sstream> 26#include <sstream>
26 27
27#include "util.h" 28#include "util.h"
28 29
29extern size_t shstr_alloc; 30extern size_t shstr_alloc;
30 31
31extern int buf_overflow (const char *buf1, const char *buf2, int bufsize); 32extern int buf_overflow (const char *buf1, const char *buf2, int bufsize);
32 33
34// this class is a non-refcounted shared string
35// it cannot be used to create or store shared strings, but
36// it can be used to apss shared strings around, i.e. as function arguments
37// or return values. their lifetime must not span a gc () call, i.e.
38// they are only valid as temporary values within the same server tick.
33struct shstr 39struct shstr_tmp
34{ 40{
35 static const char *null; 41 static const char *null;
36 42
37 const char *s; 43 const char *s;
38 44
39 static int &refcnt (const char *s)
40 {
41 return *((int *)s - 1);
42 }
43
44 static int &length (const char *s) 45 static unsigned int &length (const char *s)
45 { 46 {
46 return *((int *)s - 2); 47 return *((unsigned int *)s - 2);
47 } 48 }
48 49
49 int &refcnt () const 50 int length () const
51 {
52 return length (s);
53 }
54
55 // returns whether this shared string begins with the given prefix,
56 // used mainly for searches when users give only the start of a name.
57 bool starts_with (const char *prefix) const
58 {
59 int plen = strlen (prefix);
60
61 return length () >= plen && !strncasecmp (s, prefix, plen);
62 }
63
64 bool contains (const char *substring) const
65 {
66 return strstr (s, substring);
67 }
68
69 shstr_tmp ()
70 : s (null)
71 {
72 }
73
74 shstr_tmp (const shstr_tmp &sh)
75 : s (sh.s)
76 {
77 }
78
79 shstr_tmp operator =(const shstr_tmp &sh)
80 {
81 s = sh.s;
82
83 return *this;
84 }
85
86 // this is used for informational messages and the like
87 const char *operator &() const { return s; }
88
89 operator const char *() const { return s == null ? 0 : s; }
90};
91
92inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
93{
94 return a.s == b.s;
95}
96
97inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
98{
99 return a.s != b.s;
100}
101
102inline int strlen (const shstr_tmp &sh)
103{
104 return sh.length ();
105}
106
107// undefined external reference to catch people using strcmp when they shouldn't
108int strcmp (const shstr_tmp &a, const shstr_tmp &b);
109
110static std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
111{
112 o.write (sh.s, sh.length ());
113
114 return o;
115}
116
117struct shstr : shstr_tmp
118{
119 static unsigned int &refcnt (const char *s)
120 {
121 return *((unsigned int *)s - 1);
122 }
123
124 unsigned int &refcnt () const
50 { 125 {
51 return refcnt (s); 126 return refcnt (s);
52 } 127 }
53 128
54 int length () const 129 shstr ()
55 { 130 {
56 return length (s);
57 }
58
59 // returns wether this shared string begins with the given prefix,
60 // used mainly for searched when users give only the start of a name.
61 bool begins_with (const char *prefix) const
62 {
63 int plen = strlen (prefix);
64 return !strncasecmp (s, prefix, plen) && length () >= plen;
65 } 131 }
66 132
67 static const char *find (const char *s); 133 static const char *find (const char *s);
68 static const char *intern (const char *s); 134 static const char *intern (const char *s);
69 135
70 static void gc (); // garbage collect a few strings 136 static void gc (); // garbage collect a few strings
71 137
72 // this is used for informational messages and the like
73 const char *operator &() const { return s; }
74
75 const char &operator [](int i) const { return s[i]; }
76 operator const char *() const { return s == null ? 0 : s; }
77
78 shstr ()
79 : s (null)
80 {
81 }
82
83 shstr (const shstr &sh) 138 shstr (const shstr &sh)
84 : s (sh.s) 139 : shstr_tmp (sh)
85 { 140 {
86 ++refcnt (); 141 ++refcnt ();
87 } 142 }
88 143
144 shstr (const shstr_tmp &sh)
145 : shstr_tmp (sh)
146 {
147 ++refcnt ();
148 }
149
89 explicit shstr (const char *s) 150 explicit shstr (const char *str)
90 : s (intern (s))
91 { 151 {
152 s = is_constant (str) && !str ? null : intern (str);
92 } 153 }
93 154
94 ~shstr () 155 ~shstr ()
95 { 156 {
96 --refcnt (); 157 --refcnt ();
97 } 158 }
98 159
160 using shstr_tmp::operator &;
161 using shstr_tmp::operator const char *;
162
163 // (note: not the copy constructor)
99 const shstr &operator =(const shstr &sh) 164 shstr &operator =(const shstr_tmp &sh)
100 { 165 {
101 --refcnt (); 166 --refcnt ();
102 s = sh.s; 167 s = sh.s;
103 ++refcnt (); 168 ++refcnt ();
104 169
105 return *this; 170 return *this;
106 } 171 }
107 172
173 // here it comes
174 shstr &operator =(const shstr &sh)
175 {
176 return (*this) = (shstr_tmp)sh;
177 }
178
179 // shstr_tmp doesn't have this one
108 const shstr &operator =(const char *str) 180 shstr &operator =(const char *str)
109 { 181 {
110 --refcnt (); 182 --refcnt ();
111 183 s = is_constant (str) && !str ? null : intern (str);
112 // this optimises the important case of str == constant 0
113 if (is_constant (str))
114 s = str ? intern (str) : null;
115 else
116 s = intern (str);
117 184
118 return *this; 185 return *this;
119 } 186 }
120
121 bool operator !=(const shstr &b)
122 {
123 return !(*this == b);
124 }
125}; 187};
126 188
127inline bool operator ==(const shstr &a, const shstr &b)
128{
129 return a.s == b.s;
130}
131
132inline int strlen (const shstr &sh)
133{
134 return sh.length ();
135}
136
137inline int strcmp (const shstr &a, const shstr &b)
138{
139 // TODO: use this to find all the occurences of people using strcmp
140 // all uses should be bogus, as we should be never interested in
141 // comparing shstr's alphabetically
142#if 0
143 extern void do_not_use_strcmp_to_compare_shstr_values ();
144 do_not_use_strcmp_to_compare_shstr_values ();
145#endif
146 return a != b;
147}
148
149static std::ostream &operator <<(std::ostream &o, const shstr &sh)
150{
151 o.write (sh.s, sh.length ());
152 return o;
153}
154
155// only good for mass comparisons to shstr objects 189// only good for mass comparisons to shstr objects, or very
190// temporary passing, basically a non-refcounted shstr
156struct shstr_cmp 191struct shstr_cmp
157{ 192{
158 const char *s; 193 const char *s;
159 194
160 explicit shstr_cmp (const char *s) 195 explicit shstr_cmp (const char *str)
161 : s (shstr::find (s)) 196 : s (shstr::find (str))
162 { 197 {
163 } 198 }
164 199
165 shstr_cmp (const shstr_cmp &sh) 200 shstr_cmp (const shstr_cmp &sh)
166 : s (sh.s) 201 : s (sh.s)
… …
173 } 208 }
174 209
175 // this is used for informational messages and the like 210 // this is used for informational messages and the like
176 const char *operator &() const { return s; } 211 const char *operator &() const { return s; }
177 212
178 shstr_cmp &operator =(const shstr_cmp sh) { s = sh.s; return *this; } 213 shstr_cmp operator =(const shstr_cmp sh) { s = sh.s; return *this; }
179 operator const char *() const { return s; } 214 operator const char *() const { return s; }
180}; 215};
181 216
182inline bool operator ==(const shstr_cmp &a, const shstr &b) 217inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
183{ 218{
184 return a.s == b.s; 219 return a.s == b.s;
185} 220}
186 221
187inline bool operator ==(const shstr &a, const shstr_cmp &b) 222inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
188{ 223{
189 return b == a; 224 return a.s == b.s;
190} 225}
191 226
192extern const shstr shstr_null; 227extern const shstr shstr_null;
193 228
194#define def(str) extern const shstr shstr_ ## str; 229#define def(str) extern const shstr shstr_ ## str;

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